JSF - UICommand component not rendering properly
2:12 PM 7/11/2007
by Nirav Assar
Overview
It was discovered that in certain situations a UICommand component does not bind properly to its associated action method in the managed bean. The symptoms of this situation occur when you have a page with an action, and you click the action and nothing occurs. The page seems like it submits, but no code inside the action method of the managed bean gets executed and no errors are generated in the console!
Problem
The problem arises when you have a managed bean in request scope and you have a UICommand, either a commandLink or commandButton, associated to the bean. In addition this UICommand component has a rendered attribute tag (boolean value) that uses a managed bean method to tell it whether is renders or not. Even if the component gets rendered to the screen, the component does not get binded to the action method in the request scoped bean. This is a problem with JSF and may be due to the fact that the component gets rendered, but since the bean is not created until a request is submitted, the component never gets binded to an action. Therefore, nothing in the action method ever gets executed.
Analysis
Thus is seems like if you want to dynamically render a submit type component, such as a button or a link, you cannot effectivley do that with a bean in request scope. You'll have to place it session scope, which will work fine. Another option is to render the buttons all the time, but based on some scenario, using the "disabled" attribute to prevent a user from using the action. The "disable" attribute can access a boolean method in the managed bean.
You could also use Javascript to hide the already rendered button on certain circumstance. However this would require javascript knowing the state of the domain objects/and or managed bean state.
References:
http://forum.java.sun.com/thread.jspa?threadID=5127437&messageID=9461810
